Function atom_bond_sum_connectivity 

pub fn atom_bond_sum_connectivity(graph: &Graph) -> IgraphResult<f64>

Compute the atom-bond sum-connectivity index.

ABS(G) = Σ_{(u,v)∈E} √((d_u + d_v - 2) / (d_u + d_v))

Self-loops and degenerate edges are skipped.

Examples

use rust_igraph::{Graph, atom_bond_sum_connectivity};

// Path 0-1-2: degrees [1,2,1]
// edge(0,1): √((3-2)/3) = √(1/3)
// edge(1,2): same
// ABS = 2/√3
let g = Graph::from_edges(&[(0,1),(1,2)], false, Some(3)).unwrap();
assert!((atom_bond_sum_connectivity(&g).unwrap() - 2.0/3.0_f64.sqrt()).abs() < 1e-10);